PROJECT SUMMARY/ABSTRACT Bone marrow and trephine biopsy (BMTB) is the gold standard for diagnosing and monitoring hematological disorders and malignancies. Although BMTB procedures rarely cause serious adverse events, the number of non-diagnostic biopsies should be minimized because repeated testing delays diagnosis and treatment, consumes additional healthcare resources, and causes unnecessary patient anxiety and discomfort. World Health Organization guidelines recommend that bone marrow biopsy cores exceed 1.5 cm in length, however multiple clinical trials have reported that 20 ? 50 % of core lengths are ? 1.0 cm, suggesting that these clinical recommendations are not regularly met. This conclusion is further supported by the finding that between 5 ? 25 % of BMTB specimens are deemed non-diagnostic by pathology, often necessitating a repeat BMTB procedure, referral for radiographic guidance of the BMTB procedure, or ultimately resulting in an ambiguous or false negative diagnosis. The goal of this Phase II project is to finalize the design and fabrication of a clinical-trial-ready imaging system (Accuro 3S) for real-time 3D image guidance of bone marrow trephine biopsy procedures at the bedside. The key technological innovations of this project include: (i) the design of a miniaturized 3D ultrasound imaging probe, (ii) the development of advanced bone-specific imaging and 3D rendering technologies for generating volumetric reconstructions of the patient's iliac crest in real-time, and (iii) the implementation of an image processing algorithm that automatically detects the posterior iliac crest and assists with automated needle guidance to the target anatomy to facilitate biopsy acquisition. The intent of these technologies is to provide an intuitive visualization of the iliac crest and to avoid difficulties associated with ultrasound image interpretation when conducting an image-guided interventional procedure. Core technologies will be developed and tested via extensive in vitro imaging studies of anatomically correct phantoms prior to pre-clinical validation in a human cadaveric specimens. The impact of the proposed solution is a significant improvement in BMTB success rates and a reduced rate of referral for radiographic guidance. These effects are expected to reduce delays in BMTB acquisition, reduce patient exposure to ionizing radiation, and reduce costs due to the need for fewer repeat biopsies and fewer referrals for radiographic guidance. Together, the annual costs due to referral for radiographic guidance, repeat BMTB procedures, and costs stemming from diagnostic errors exceed $480M/yr. For these reasons, BMTB specimen retrieval at the bedside in the hematology clinic is the preferred biopsy technique. The technological solutions proposed in this Phase II application seek to enable improved outcomes of BMTB procedures performed at the bedside. Finally, the total US market size for this device is estimated to be $230M/yr, supporting the commercial viability of the proposed technology development efforts.